Knit fabrics possessing improved durable press and comfort properties

ABSTRACT

A DURABLE PRESS TEXTILE HAVING IMPROVED SHAPE RETENTION, COMFORT AND WEAR CHARACTERISTICS WHICH COMPRISES A KNITTED FABRIC HAVING A FACE CONSISTING AT LEAST ESSENTIALLY OF NON-CELLULOSIC YARN (WHICH IS FREE FROM DURABLE PRESS FINISH) AND A BACK CONSISTING AT LEAST IN PART OF CELLULOSIC YARN, THE BACK HAVINGG A DURABLE PRESS REACTANT FINISH THEREON. THE PRODUCT MAY BE MADE BY KNITTING A SINGLE, DOUBLE OR WRAP KNIT FABRIC, PRESENSITIZING THE CELLULOSIC BACK BY APPLICATION THERETO OF A DURABLE PRESS RESIN, PRESSING AND CURING.

United States Patent 9 3,738,902 KNIT FABRICS POSSESSING IMPROVED DURA-BLE-PRESS AND COMFORT PROPERTIES John Dean Turner, Greensboro, N.C.,assignor to Burlington Industries, Inc., Greensboro, N.C. No Drawing.Filed Apr. 1, 1971, Ser. No. 130,510

Int. Cl. B32b 7/00 US. Cl. 161-89 6 Claims ABSTRACT OF THE DISCLOSURE Adurable press textile having improved shape retention, comfort and wearcharacteristics which comprises a knitted fabric having a faceconsisting at least essentially of non-cellulosic yarn (which is freefrom durable press finish) and a back consisting at least in part ofcellulosic yarn, the back having a durable press reactant finishthereon. The product may be made by knitting a single, double or warpknit fabric, presensitizing the cellulosic back by application theretoof a durable press resin, pressing and curing.

The present invention is concerned with knit fabrics which demonstrateimproved durable-press, wear and comfort properties. The invention is ofparticular importance in connection with knit fabrics (single knit,double knit or warp knit) containing or consisting of polyester faceyarn, although the invention also contemplates the use of othersynthetic thermoplastic yarns, -e.g. nylon, acrylics, cellulosetriacetate, etc., and/or wool, in lieu of, or in addition to, polyesteras the face yarn.

As background to the invention, it is noted that conventional knitfabrics, for example, knits composed entirely or essentially ofpolyester, suffer from several disadvantages. One problem is that 100%polyester knits cannot consistently be given a durable, press orpleat,,at least in the absence of special processing techniques.Apparently this is due, at least to some extent, to yarn movement in theknit structure, the movement causing pleats or creases to become roundedduring wear. Whatever the explanation, however, the difficulty ofconsistently imparting a durable press to polyester knits iswell-recognized and has been a limiting factor in the nature of the useof such products.

Another problem with conventional polyester knits is their lack ofcomfort to the wearer. This is due to such factors as feel, staticpickup, low moisture absorption, and the like. These propertydisadvantages can be minimized or overcome by the application of certainfinishes but, generally speaking, these finishes create'other problemssuch as stiffness or tackiness. Similar problems are encountered in thecase of conventional knits made with other synthetics, e.g. nylon.

Cotton and like cellulosics are well known for their comfort propertiesbut, when a durable press finish is applied thereto, other advantageousproperties, particularly abrasion resistance, are undesirably affected.

The principal object of the present; invention is to provide durablepress knit textiles, e.g. double or single knits or warp knits, whichare free from the disadvantages noted above. A specific object of theinvention'is to provide knit fabrics containing polyester and cellulosicyarns which have better durable press, comfortand wear properties thanotherwise possible using conventional techniques and/ or knitconstructions. Other objects will also be apparent from the followingdetailed description of the invention.

Broadly stated, the objects of the invention are realized by providingaknit fabric having a face consisting at least essentially ofnon-cellulosic yarn and a back consisting at least in part of cellulosicyarn, the back having a durable press reactant finish thereon. Suchproduct may be prepared by knitting a fabric, for example, a double knitfabric, having a face composed exclusively of polyester filament yarnsand a back consisting at least in part of cellulosic yarn, e.g. filamentrayon, presensitizing the cellulosic back by the application thereto ofa durable press resin, preparing a garment from the thus treated fabric,pressing and curing.

A wide variety of knit constructions can be made according to theinvention providing the face and back are predominantly made ofdifferent fibers as described above. Appropriate apparatus for preparingsuch knit constructions are well known and includes such conventionaltypes of single, double and warp knitting apparatus as, for example,Raschel or tricot machines. Typical apparel constructions include, inthe case of double knits, the socalled Milano Rib and Ponti de Roma. Thefirst of these (Milano Rib) requires three yarn feeds, identifiable asthe cylinder (or face), rib (face and back) and dial (or back) feeds,while the Ponti de Roma requires four feeds, two being identifiable asinterlocking, another as the dial or back feed and the fourth as thecylinder or face feed.

As indicated the face of the present fabric is preferably polyester,most advantageously polyester multifilament (e.g. /20 or /34 polyesterfilament yarn). Spun yarns may also be used but best results,particularly in respect of pilling resistance, are obtained if filamentyarn is used for the face. Other synthetic thermoplastic yarns or woolas noted above may also be used in lieu of the polyester or blendedtherewith. Preferably, however, at least 50% by weight of the face ispolyester filament yarn. The face may also include a minor amount ofcellulosic filament or, in certain cases, spun yarn but preferably thecellulosic content in the face does not exceed 35% by weight of thetotal face yarn.

As for the back yarn, considerable variation is possible provided theback includes at least some cellulosic yarn (e.g. 20% or more by weightbased on the total weight of back yarn. Filament rayon is preferred asthe cellulosic yarn component for the back of the fabric. A typicalexample thereof suitable for use herein is 100/40/25 filament rayon,although obviously other rayon filament yarns may be used. The rayonyarn may be regular rayon, high wet modulus rayon or blends of these,with each other or with other synthetic fibers. Other possibilities forthe back include, for example, spun yarns comprising polyester andcotton or polyester and rayon, or plied polyester/rayon filament yarn.When maximum strength is desired, it is preferred to use polyesterfilament for the back in conjunction with the cellulosic component. Insuch cases, the cellulosic component, e.g. rayon filament is wrappedaround a polyester filament core or the two yarns may be plied together.

Best overall results seem to be obtained when the back of the fabricdoes not have too high a cellulosic content (cg. not in excess of 60-75%by weight). The back may be completely cellulosic in cases where thefabric is not subjected to considerable strain or tension in usealthough normally, as indicated, it is preferred to use a combination ofcellulosic and non-cellulosic yarn, especially polyester yarn, for theback.

Any of the conventional durable press resins, and curing catalyststherefor, may be used for present purposes. Typically the resin may be awater-soluble precondensate of formaldehyde with such amino compounds asurea, thiourea, cyclic ethylene ureas (e.g. dimethylol cyclic ethyleneurea or dimethylol dihydroxy cyclic ethylene urea), melamine, ethylcarbamate, urons, triazones and triazines or mixtures thereof. Blockedisocyanates may also be effectively used. Suitable curing catalysts Kinclude, without being limited thereto, magnesium chloride or nitrate orzinc chloride or nitrate; various amine hydrochlorides such as2-amino-2-rnethyl-l-propanol hydrochloride, or triethanol-aminehydrochloride; and ammonium salts such as ammonium chloride, tartrate,citrate, formate, oxalate, nitrate or ammonium ethyl phosphate orammonium dihydrogen phosphate or the like. These catalysts may becombined, e.g. zinc nitrate and ammonium chloride may be used together,and/or catalyst modifiers may be included as necessary to achievedesired effects, e.g. to increase or decrease catalyst activity.

Typically, the finish of the invention will comprise, on a weight basis,from 5-35% durable press resin (usually 10-25%); 0.17% catalyst; and to(usually 0.2- 2%) surfactant, balance water with the optional addition(e.g. 010%) of other conventional durable press components such asextenders, softeners or the like.

The finish is applied to the fabric back in any convenient fashion, e.g.by dipping or spraying but preferably by padding. It generally does notmatter that finish is also applied to the face although in some cases itmay be preferable to essentially limit application of the finish to theback by using a kiss roll. As noted above, however, this is usually notessential, particularly when the face is predominantly polyester or likehydrophobic material since the finish will stay on the surface of suchyarns rather than impregnating the same and is not detrimental to theproperties of the fabric.

The amount of the finish applied to the fabric can be widely varied andis dependent on such factors as the nature and construction of thefabric, its intended use, etc. Usually, however, wet pickup will fall inthe range of 30- 75% by weight of the fabric. The thus treated fabric isthen dried, usually at 190-200 F. for l5 minutes, to a moisture contentin the order of 5-10% by weight.

The dried fabric is then cut into the desired shape, sewn into a garmentor other article, pressed on a hot head press or the equivalent andcured. Conventional pressing and curing conditions may be used, e.g.pressing on the hot head press may involve application of heat at 300325F. for 5-15 seconds and curing may be accomplished by oven baking orheating at 300350 F. for 5-15 minutes. As an alternative, pressing andcuring may be carried out simultaneously on a hot head press or thelike.

The invention is illustrated, but not limited, by the following exampleswherein percentages are by weight unless otherwise indicated.

EXAMPLE 1 A Milano Rib double knit construction was prepared using100/20 filament polyester yarn for the face and 100/ 40/ 25 filamentrayon and the filament polyester yarn together for the back as follows:

Feed #l--Cylinder (face)polyester Feed #2-1 x 1 Rib (face &back)-polyester Feed #3Dial (back)1 end polyester, 1 end rayon Theresulting fabric was then scoured with perchloroethylene, ironed toremove wrinkles, heat set (at 400 F. for 30 seconds) on a pin frame andthen padded with an aqueous durable press resin solution having thefollowing composition:

25% dimethylol dihydroxy ethylene urea (45% aqueous solution) 5% zincnitrate (50% aqueous solution) 2% Emmersoft 7777 (triglyceride typesoftener from Emery Industries) 0.1% non-ionic wetting agent (nonylphenol ethylene oxide adduct) Wet pickup amounted to about 60%.

The fabric was dried on a pin frame at 200 F. for 3 minutes and thenconstructed into pant leg bottoms, pressed on a hot head press at 325 F.for 5 seconds steam, 5 seconds bake and 5 seconds vacuum followed'bybaking in an oven at 330 F. for 15 minutes.

v The thus pressed and cured pant leg bottoms were then washed fivetimes at F. (in a Sears Kenmore 600 washer), on a wash-and-wear cycleusing warm water and tumble dried. The leg bottoms exhibited excellentshape and pleat retention even after the repeated washings.

EXAMPLE 2 Example 1 was repeated using the same polyester and rayonyarns in the following constructions:

Ponti de Roma Construction #1 Feed l--Interlock-polyester Feed#2-Interlock-polyester Feed #3Dial (back)rayon Feed #4'Cylinder(face)-polyester Construction #2 Feed #1Interlockpolyester Feed#2'Interlockrayon Feed #3Dialpolyester Feed #4Cylinderrayon Milano RibConstruction #3 Feed #1Cylinder (face)-polyester Feed #2-1 x 1 Rib (face& back)polyester Feed #3Dial (back)polyester Construction #4' Feed#1Cylinderpolyester Feed #21 X 1 Ribpolyester Feed #3Dial1 endpolyester, 1 end rayon Construction #5 Feed lCylinderpolyester Feed #21X 1 Ribpolyester Feed #3-Dialrayon2 ends PHYSICAL TEST RESULTS Resintreated (except 3, Le. 100% polyester) Constructions Accelerotorabrasion loss, g.:

Face 14. 9 35. 4 0.1 0.2 3. 2

Back 16. 3 35. 3 0. 1 0. l 13. 0 Mullen bursting test; (lbs.) 58 33 13056 Crease angles (warp & fill),

Wet- 325 225 281 315 319 Crease retention 5 5 2 5 5 DISCUSSION OFRESULTS (A) General Construction #4 gave the best balance of physicalproperties with constructions 1 and 5 next best.

(B) Accelerotor abrasion loss The more protected the filament rayon wasin the constructions the better the abrasion resistance. Construction #4was particularly good in this respect.

(C) Mullen bursting test Construction #4 was particularly good in thisrespect because the filament rayon was plied together with the polyesterfilament, thus giving added strength.

(D) Crease angles Crease angles were excellent for all the constructionsexcept #2.

(E) Crease retention (E) Surface appearance Crease retention, basedonestimated values f from All the samples exhibited a (excellent)rating. 1-5, was excellent (5) for all the'constructions except F #4(the 100% polyester construction). I I Reslstance to pining Theconstructions with cellulosic yarns in the back,i.e. 5 The samples showthat a preponderance of spun constructions 1, 4 and 5, also showed muchgreater abyarns on the face of the fabric generally results in ansorbency rates than the others. For instance, the rate at increase inthe tendency to pill. The tendency to pill, which a P of Water absorbedbYCOHStI'IEtiOIlS 4 therefiore, is directly proportional to the amountof and 5 y be of the O r of times h absorbency spun yarn in the face ofthe product (compare values P construction 1511113 Providing m greatercomfort of 1 indicating poor resistance to pilling for construcm wealtions F, G and H to value of 5, representin no pilling EXAMPLE 3 forother constructions). g

The following Milano Rib constructions were prepared (G) Resistance todifi ti l wear as indicated and then processed in the manner of Example1 except that in this case the fabrics were scoured and AuIthe samplescontalmng Pnmanly Spun Y (con' cross-dyed after heat setting but-beforeresin application: StI'I-ICUOIIS L and were rated 1 (1 Construction Facecylinder I i v I y Face and back 1 x 1 rib 1 f Back 3 A log/ polyester100/20 polyester filamentn 1 end 100/20 polyester filament (core); 1 end100/40/25 rayon.

ament. 1 it B .00 do 1 end 100/20 polyester filament (core); 1 end /1 50polyester] 50 cotton spun yarn. O do do 28/1 50/50 polyester/cotton spunyarn.

100/20 polyester filament-2 ends 1 0 d 00/ 0 polyester filament (core);1 end 400/40/25 rayon. d0 1 and 100120 polyester filament (core); 1 end100/40/25 1ayon-... 100/20 p lyester filament.

28/1 /50 poly- /20 polyester filament 28/1 50/50 polyester/cotton spunyarn.

ester/rayon I v spun yarn. G 35/1 0/50 poly- 35/1 50/50 polyester/cottonspun yam 35/1 50/50 polyester/cotton spun yarn.

ester/cotton spun yarn. H 28/1 0/50 poly- 28/1 50/50 polyester/rayonspun yarn. 28/1 50/60 polyester/rayon spun yarn.

ester/rayon I 1 I spun yarn. I 10%20 polyester 100/20 polyester filn'mAnf' 100/20 polyester filament.

ament. 3' 24/1 50/50 24/1 50/50 Dacron/cotton spun 24/1.50I50 50/50Dacron/cotton spun.

Dacron/cotton I spun a I K do 100/20 polyester filament I 7 24/1 50/50Dacron/cotton spnn. L 31/1 50/50 31/1 50/50 Dacron/cotton spun, 31/150/50 Dacron/cotton spun.

Dacron/cotton v 1 I I a 1 spun. M do 100/20 polyester filament D0.

The above constructions were tested for various physiboth on the faceand back. The samples with the face cal properties as shown below withthe results indicated: yarns all filament polyester (constructions A-D)ex- Construction I A1 B C DEF GHIJKLM Brusting strength (Mullen tester),lbs 1 129 114 141 97 35 117 92 72 95 120 109 80 91 Crease resistanceMonsanto tester a I I I I wan: 141 145 '147 149 150 131 125 129 133 144121 13s 5 V 137 133 115 129 158 151 152 148 140 144 154 154 'wales. 13s147 159 155 146 145 133 114 112 115 135 115 130 Cour s 153 118 117 94'105 153 1 3 131 122 124 133 130 146 d 10 F. b1 (1 d 0 (11mm Bung 5 mm ame Mm em 1.0 0.5. 1.5 05 0.5 1.0 0.5 2.5 0.5 0. 0 2.0 2,0 0.5 1.5 2%) 2g1g 0.2 2.2 2.2 12 Lg Lg 1.5 12 Surface appearance (1 laundering at 105F. tumb 5 5 5 Resistance to gigingz liiandom tumble me'thod- 5 5 5 I 5 51 1 1 5 1 1 1 1 Reslgtance to erent a wear. 5 5 i5 1 5 1 1 1 5 1 1 1 1 55 5 5 5 1 1 1 5 1 1 1 1 DISCUSSION OF RESULTS 7 s I hibited class 5(excellent) rating on the face.

(A) Handle 1 60 The above results indicate that constructions A-D,

.. v v I 1 containing all polyester filament face yarns with rayon Allthe S m wnslstmg Pnmanly PY E or other cellulosic in the back of thefabric, give the best were extremely -Th? samples contammg? P33 3 1balance of properties when processed according to the filament Y had acrisper handle- The softness was inventionLThese fabrics also showedoutstanding antidirectly proportioned to the, amount of spun yarnsr g" 5Static proper/56$ (B) Bursting strength (Mullen,tester) By cross-dyeingfabrics as described in Example 3 it I is possible to obtain a widevariety of pattern or random All the samples appgared to have adequatestrength color effects on the face and the back of the fabric basedCrease I M on the dilferent dyeing characteristics of the yarns in- Thesamples containing primarily filament yarns ex- 70 volved and theknitting pattern selected. hibited higher crease angles. -While theforegoing examples illustrate the invention as applied to double knitconstructions, corresponding re- (D) Shnnkage sults can be obtained withsingle knit (jersey) and warp The highest shrinkage of any of thesamples was 2.5% knit constructions, e.g. tricot or Raschel knits,wherein With the average being between one and two percent. 75 the backis at least partly cellulosic and the face is mainly polyester or othersynthetic or non-cellulosic yarn. Useful yarn combinations for suchconstructions include filament rayon either wrapped around a polyestercore or plied with polyester for the back and for the face, polyesterfilament yarn or spun yarn, as such or blended with, for example, woolor other staple, preferably non-cellulosic. When filament rayon is usedin the back of warp knit fabrics in particular, it is preferable to wrapor ply the yarn with another yarn (e.g. polyester filament) or use aspun blend (such as polyester/rayon) to minimize strain on the rayonback. Representative warp knit fabrics according to the inventioninclude, for example, warp knit jersey containing 150/34 texturedpolyester filament in the face and 150/25/40 rayon filament in the backor 22/1 spun polyester in the face and 20/1 polyester-rayon spun yarnfor the back. A particularly useful single knit jersey construction forprocessing according to the invention comprises a 100/20 polyesterjersey feed a's'th'e face and, as the lay-in feed or back, an end of100/40 rayon wrapped around an end of 100/ polyester yarn as the core.It will be recognized, however, that these combinations are only givenfor purposes of illustration and V EXAMPLE 4 A single knit jerseyconstruction was prepared on a 20" 28-cut unit. The construction includea La Coste stitch for the jersey feeds in combination with lay-in feeds.The jersey feeds were composed of 100/20 polyester filament yarn whilethe lay-in feeds comprised 1 end of 100/40 rayon and 1 end of 100/20polyester (core), i.e. the rayon was wrapped around the polyester core.

The resulting jersey construction was then dry-cleaned, heat-set at 400F. for 30 seconds on a pin frame, scoured and cross-dyed, and thenpadded with aqueous durable press resin solution, dried, made into pantleg bottoms, pressed and cured, all as in Example 1. The thus pressedfilament yarn for the face and 150/ 2.5/40 dull filament rayon for theback. The fabric was processed and tested as in Example 3 with thefollowing results:

Bursting strength, lbs. 95 Crease resistance,

Dry-Wales 110 Courses 127 Wet-Wales 71 Courses 149 Surface appearance 5Resistance to pilling 5 Resistance to differential wear:

Back 5 Face 5 Shrinkage, percent:

-Wales 2.5 V H Courses 4.5 Crease retention L; 4.0

i The handle and appearance of the fabric were excellent and notimpaired by the resin treatment. Strength was satisfactory but could beincreased if desired by wrapping "'the rayon back yarn around polyesterfilament yarn so and cured leg bottoms were then washed as in Example 1v Pleat retention: I v

After 5 launderings (105 F.), tumble dried 4.0

As will be evident, the above jersey knit product demonstrated anoutstanding balance of durable-press, resistance to differential wear,strength, high wet and dry crease resistance, and resistance to pilling.Additionally, the product had excellent hand and comfort properties.

EXAMPLE 5 A textured polyester/rayon jersey fabric was made by warpknitting (tricot) using 150/34 textured polyester that load on thefabric would be transferred to the polyester yarn.

The normal procedure for dyeing warp knits containing textured polyesteryarn is to heat-set after dyeing to bulk the textured polyester but thefabric of Example 5 was uniformly and otherwise satisfactorily dyed byfollowing the sequence of steps outlined in Example 3 including scouringand heat-setting before dyeing.

It will be recognized that various modifications may be made in theinvention described herein. Hence, the scope of the invention is definedin the following claims wherein:

I claim:

1. A pressed and cured textile having improved shape retention and wearcharacteristics which comprises a knitted fabric having a faceconsisting at least essentially of polyester filament yarn and a backconsisting essentially of filament rayon yarn wrapped or plied with apolyester filament yarn, the. amount of rayon yarn in the backcomprising from 20-75% by weight of the yarn in the ,back,, the backhaving a cured thermosetting durable press resin finish thereon.

2. A textile according to claim 1 in the form of a garment which hasbeen pressed and cured.

3. A textile according to claim 1 comprising a double knit fabric.

4. A textile according to claim 1 comprising a warp knit fabric.

5. A textile according to claim 1 comprising a single knit fabric.

H 6. A textile according to claim 1 which includes not more than 35%. byweight oellulosic yarn in the face.

References Cited UNITED STATES PATENTS GEORGE F. LESMES, PrimaryExaminer J. J. BELL, Assistant Examiner I Us. 01. X.R. 66202; 151-432;2-69; s 115.7

